April J. Chambers, PhD, the candidate for this Mentored Research Scientist Development Award (K01), is a Research Assistant Professor at the University of Pittsburgh. Through mentorship, research, and training, this career award will help me achieve my long term goal of developing an independent line of research in ergonomic issues unique to musculoskeletal injuries in the workplace. It will teach me techniques that are not typically used in the field of traditional ergonomics. Thus, I will be able to advance the fiel of occupational biomechanics by using this training in state of the art techniques and methodologies to achieve a better understanding of underlying mechanisms of musculoskeletal injuries. It will further provide me the opportunity to develop research collaborations with a number of well-respected scientists and increase my knowledge and competency in ergonomics and occupational biomechanics. I plan to apply for a NIOSH R01 award with the data acquired from this proposed research. The proposed project is focused on the important issue of injury and discomfort related to prolonged standing. Prolonged standing in the workplace is a significant ergonomic problem that is directly linked to musculoskeletal injuries, health problems and high economic costs. The general hypothesis of the proposed project is that prolonged standing impacts tissues within the joints and muscles, which in-turn results in increased pain and risk of injury. However, the specific changes that occur during standing are not, as of yet, understood. The project objective is to investigate the impact of prolonged standing on in vivo changes in articular cartilage deformation within the knee joint and lower extremity muscle characteristics. A second objective is to investigate the impact of human and environmental factors on these effects. A total of 40 young adults will participate in the experiments. Novel and innovative methodologies including dynamic stereo x-ray, near-infrared spectroscopy, electromyography, and biomechanical analysis will be employed to assess the effect of prolonged standing on measures of joint and muscle injury risk. Additionally, the impact of obesity and flooring on these novel objective measures will be examined. This project will provide critical knowledge regarding changes in the lower extremities due to prolonged standing that could result in injury. This research, in addition to a series of studies that would naturally follow in its path, will lead to new methods of evaluating injury risk and more effective interventions to reduce musculoskeletal injuries in the workplace. Since prolonged standing is common in the workplace, this proposed plan will impact multiple industry sectors including Healthcare and Social Assistance, Manufacturing, Mining, Public Safety, Transportation, Warehousing and Utilities, Wholesale and Retail Trade. The NIOSH cross-sector programs being addressed are Engineering Controls, Musculoskeletal Disorders, Prevention through Design, and Training Grants.